If the endothelial cells of the blood vessels in the body did not possess adhesion molecules, which of the following would occur?

• A. The immune cells which respond to infection or injury would not be able to leave the blood stream.
• B. The immune cells would not be able to detect where the infection is in the body.
• C. The immune cells would not be able to phagocytose the infecting microbes and damaged tissue.
• D. The blood vessels would adhere to the immune cells allowing them entry to infected regions of the body.

Answer: (A)

Verified step by step guidance

1. Understand the role of endothelial cells in blood vessels: Endothelial cells line the interior surface of blood vessels and play a crucial role in regulating the passage of materials and the transit of white blood cells into and out of the bloodstream.
2. Learn about adhesion molecules: These molecules are proteins located on the surface of endothelial cells that facilitate the binding of immune cells to the blood vessel walls, allowing them to exit the bloodstream and reach sites of infection or injury.
3. Consider the consequences of lacking adhesion molecules: Without adhesion molecules, immune cells would not be able to adhere to the endothelial cells, preventing them from leaving the bloodstream and reaching the site of infection or injury.
4. Evaluate the options given in the problem: Analyze each option to determine which one correctly describes the consequence of endothelial cells lacking adhesion molecules.
5. Identify the correct consequence: The absence of adhesion molecules would mean immune cells cannot leave the bloodstream, which aligns with the option stating that immune cells would not be able to leave the bloodstream to respond to infection or injury.